Structured catalyst for POX reforming of gasoline for fuel-cell powered vehicles applications and a method of preparing the same

ABSTRACT

The present invention relates to a structured catalyst for reforming of gasoline and a method of preparing the same, more particularly to a structured catalyst for reforming of gasoline for fuel-cell powered vehicles prepared by wash-coating the transition metal based reforming catalyst on the surface of the ceramic honeycomb support wash-coated with sub-micron sized alumina or its precursor to sufficiently increase the effective surface area and the performance of the catalyst and a method of preparing the same.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a structured catalyst for reforming ofgasoline and a method of preparing the same, more particularly to astructured catalyst for reforming of gasoline for fuel-cell poweredvehicles prepared by wash-coating the transition metal based reformingcatalyst on the surface of the ceramic honeycomb support wash-coatedwith sub-micron sized alumina or its precursor to sufficiently increasethe effective surface area and the performance of the catalyst and amethod of preparing the same.

2. Description of Related Art

Researches on fuel processors for fuel-cell powered vehicles arecurrently on the active progress worldwide. There are many challenges,such as lightweightness, compactness, durability, dynamic load, thermalbalance control, CO concentration control and startup time, indeveloping a fuel processor for a fuel-cell powered vehicle. Especially,a compact system is essential to develop an on-board gasoline fuelprocessor.

A gasoline fuel processor mounted on a fuel-cell powered vehiclecomprises a desulfurizer, an autothermal reformer (ATR), a water gasshift (WGS) reactor, a preferential partial oxidation (PROX) reactor,system equipments and controllers. For commercialization of a fuelprocessor, development of a structured catalyst capable of maintainingcatalytic activity is necessary along with development of a catalysthaving superior performance for each reaction.

Structured catalysts are used in various fields including vehiclesexhaust gas purifying catalysts, as environmental regulations on the airbecome more strict. Especially, they are used to convert nitrogen oxidesgenerated in combustion facilities, such as power plants, incineratorsand engines of ships, by selective catalytic reduction (SCR), to adsorba variety of noxious gases generated during semiconductor-manufacturingprocesses and to remove a variety of volatile organic compounds (VOCs).

As a support of structured catalyst, the monolithic type modules aremost favored. For example, they are easily found in the reactors forremoving such impurities as hydrocarbons, NOx and VOCs from exhaustgases and the honeycomb type reactors for treating vehicle exhaustgases. The honeycomb type reactors are extrusion-molded to havehoneycomb-shaped cross-sectional paths. They are used widely because ofrelatively large surface area per unit volume. A support with largesurface area and/or a catalyst are impregnated on the basic monolithictype module having regular paths parallel to the direction of gas flowby wash-coating method.

Since the introduction in the early 1970s the honeycomb type reactorshave been widely used. U.S. Pat. Nos. 4,072,471, 5,547,641 and 5,145,825disclose honeycomb reactors, reaction processes thereof, optimization ofcatalytic materials and preparing methods thereof.

However, most of the preceding researches focus on honeycomb reactorsfor removing such impurities as hydrocarbons, NOx and VOCs from vehicleexhaust gases, and there have been few researches on gasoline reformingstructured catalysts for fuel-cell powered vehicles.

In recent years, researches on processing reactions for fuel-cellpowered vehicles have been reported in Korean Pat. Application No.2002-21236, U.S. Pat. No. 6,183,703 and European Pat. No. 977,293. Theyare about heat supply method suitable for fuel reaction equipments,catalytic system array for each reaction process (POX, WGS, de-Sulfur,PROX and so forth), fuel injection method and fuel injection line systemand catalyst filling layer.

Most of the preceding researches are performed using powder type orpellet type catalysts, which increases reactor volume and pressure whenapplied to the kW level. Therefore, a structured catalyst having goodthermal stability and mechanical strength while capable of reducingreactor pressure is highly needed.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a structuredcatalyst for kW-level gasoline POX reforming in order to develop agasoline fuel processor integrated with a polymer electrode membrane(PEM) fuel cell.

It is another object of the present invention to provide a method ofpreparing a structured catalyst with significantly improved POXreforming catalytic activity comprising the steps of: preparing asupport with large surface area by wash-coating sub-micron sized aluminaon a ceramic honeycomb support; and supporting transition metal catalystpowder by wash-coating.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing the method of preparing astructured catalyst for reforming of gasoline of the present invention.

FIG. 2 is a schematic diagram of the Wash-coating system for preparingthe gasoline reforming structured catalyst of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to a structured catalyst for reforming ofgasoline for fuel-cell powered vehicles comprising a gasoline reformingtransition metal catalyst supported on a ceramic honeycomb supportwash-coated with sub-micron sized alumina, the support having a BETsurface area ranging from 20 to 60 m²/g, more preferably from 30 to 60m²/g.

The present invention also relates to a method of preparing a structuredcatalyst for reforming of gasoline comprising the steps of: 1) preparingan aqueous alumina solution with a pH 2 to 5; 2) adding 2 to 7 wt % ofpolyvinyl alcohol, 3 to 7 wt % of methyl cellulose and 1 to 5 wt % ofphosphoric acid (H₃PO₄) based on 100 wt % of the solid content of theaqueous alumina solution, stirring and ball-milling it to prepare analumina slurry; 3) coating the alumina slurry on a ceramic honeycombsupport; 4) ball-milling of gasoline reforming transition metal catalystpowder to prepare a catalyst slurry; and 5) wash-coating the catalystslurry to prepare a structured catalyst.

The present invention is further relates to a method of preparing asynthetic gas containing hydrogen and carbon monoxide from autothermalreforming reaction of gasoline, the reforming reaction performed under areaction temperature ranging from 600 to 1000° C., space velocityranging from 1,000 to 50,000 hr⁻¹ and molar ratios of H₂O/C and O/Cranging from 0.1 to 5 and 0.1 to 3 respectively in the presence of thestructured catalyst of the present invention.

Hereinafter, the present invention is described in more detail.

The present invention relates to a method of preparing a structuredcatalyst by supporting gasoline reforming transition metal catalystpowder, which is known to generate a synthetic gas containing hydrogen(H₂) and carbon monoxide (CO) in POX reforming of iso-octane, on aceramic honeycomb support by wash-coating to offer better catalyticactivity and superior adhesivity.

As the gasoline reforming transition metal catalyst powder, any one thathas catalytic activity in POX reforming reaction of iso-octane can beused. The present invention relates to a structured catalyst prepared bysupporting the above-mentioned catalyst powder along with a suitablebinder composition on a ceramic honeycomb support with large surfacearea, on which alumina or its precursor is wash-coated, by Wash-coating.A structured catalyst having good catalytic activity and superioradhesivity is obtained through control of particle size and pH,selection of binder, number of impregnations and concentration ofimpregnation solution.

Examples of the gasoline reforming transition metal catalyst used in thepresent invention are ICI catalyst; which is commercially available, andporous supported transition metal catalyst powder; which was developedby the present inventors and filed for the patent application, KoreanPat. Application No. 2002-21236.

The catalyst disclosed in Korean Pat. Application No. 2002-21236comprises 5 to 15 wt % of magnesium (Mg), as a metal preventing carbondeposition, with reference to the amount of the total catalyst and atleast two transition metals as promoters selected from the groupconsisting of Ni, Co, Fe, Mo, Cr, Ti and Zr supported on a poroussupport such as γ-alumina and silica-alumina (Si—Al). With reference tothe amount of the total catalyst, Ni may be comprised in 0.1 to 15 wt %,Co in 0.1 to 15 wt %, Fe in 2 to 15 wt %, Mo in 2 to 15 wt %, Cr in 0.1to 1.0 wt %, Ti in 0 to 0.005 wt % and Zr in 0 to 0.005 wt %.

FIG. 1 is a schematic diagram showing the method of preparing astructured catalyst for reforming of gasoline for fuel-cell poweredvehicles of the present invention. The method of preparing thestructured catalyst is described in detail referring to FIG. 1.

The first step is preparation of a pH 2 to 5 aqueous alumina solution.

Sub-micron sized γ-alumina or boehmite alumina having a particle sizeranging from 0.5 to 0.95 μm is dissolved in diluted water to prepare a30 to 45 wt % aqueous solution. Then, the pH is adjusted to 2 to 5 usingan aqueous hydrochloric acid solution as a dispersant.

The second step is preparation of an alumina slurry by adding a binderto the aqueous alumina solution.

The binder is added to the aqueous alumina solution to prepare astructured catalyst slurry having superior adhesivity. The adhesivitymay be changed by selection of binder composition and its contentcontrol. In the present invention, 2 to 7 wt % of polyvinyl alcohol, 3to 7 wt % of methyl cellulose and 1 to 5 wt % of phosphoric acid (H₃PO₄)are added to the aqueous alumina solution for 100 wt % of solid content.Then, the mixture is strongly stirred for 1 to 3 hr and zirconia ballshaving a diameter ranging from 1 to 5 mm is wet-milled to prepare awash-coating slurry. It is important to control the concentration of thealumina slurry to 35 to 45 wt % to obtain wanted alumina wash-coatingamount and BET surface area of the support.

The third step is coating of the alumina slurry on a ceramic honeycombsupport.

A ceramic honeycomb is washed several times with diluted water using anultrasonic cleaner to remove remaining impurities, and then dried in aconstant temperature/humidity chamber. Then, the alumina slurry preparedabove is coated on the ceramic honeycomb. The coated ceramic honeycombis blown with blowing air to remove excess slurry. The Wash-coating maybe a single coating or multi coating of 2 to 5 layers, if required.After wash-coating, the ceramic honeycomb is dried in a constanttemperature/humidity chamber of 60 to 110° C. and 70 to 90% relativehumidity (RH), and then calcined at 500 to 700° C. in air. The resultanthoneycomb support wash-coated with alumina has a BET surface arearanging from 20 to 60 m²/g.

The fourth step is drying of catalyst slurry.

A catalyst slurry is prepared similarly to the process of alumina slurrypreparation using an attrition mill. The binder used in the preparationof alumina slurry may be added to improve adhesivity. That is, 0 to 7 wt% of polyvinyl alcohol, 0 to 7 wt % of methyl cellulose and 0 to 5 wt %of phosphoric acid (H₃PO₄) are added to 100 wt % of the transition metalcatalyst powder as binder, and the mixture is stirred and ball-milled toprepare a catalyst slurry.

The fifth step is preparation of the structured catalyst of the presentinvention by wash-coating the catalyst slurry on the alumina wash-coatedsupport.

The catalyst slurry coating may be a single coating or multi coating of2 to 5 layers, if required. The honeycomb support is dried in a constanttemperature/humidity chamber of 60 to 110° C. and 70 to 90% relativehumidity, and then calcined at 500 to 700° C. in air.

Such prepared structured catalyst showed high catalytic activity whenapplied to ATR reaction of gasoline for fuel-cell powered vehicles. Theoptimum reaction condition to confirm the catalytic activity is:reaction temperature=600 to 1,000° C.; space velocity=1,000 to 50,000hr⁻¹, molar ratio of H₂O/C=0.1 to 5 and molar ratio of O/C=0.1 to 3.When the ATR reaction was performed under the above-mentioned condition,a synthetic gas containing hydrogen and carbon monoxide was preparedwith minimum carbon deposition and maximum resistance against sulfur.

The hydrogen gas reformed by the ATR reaction may be passed through aseries of high temperature water gas shift (HTS) reactor, lowtemperature water gas shift (LTS) reactor and/or preferential partialoxidation (PROX) reactor to reduce the CO concentration, and thenprovided to a polymer electrolyte membrane (PEM) fuel cell for afuel-cell powered vehicle.

The structured catalyst of the present invention may also be utilized ingas stations to manufacture highly pure hydrogen gases or petrochemicalprocesses to manufacture synthetic gases.

EXAMPLES

Hereinafter, the present invention is described in more detail throughExamples. However, the following Examples are only for the understandingof the present invention, and they should not be construed as limitingthe scope of the present invention.

Example 1 Preparation of Ceramic Honeycomb Support Wash-Coated withAlumina Example 1-A Honeycomb Support Wash-Coated with γ-Alumina

The Wash-coating system is shown in FIG. 2. It comprises a reactor thatwash-coats the ceramic honeycomb, an air blower that removes excessslurry, a storage tank that stores and stirs the wash-coating slurry anda liquid pump that circulates the slurry.

For the ceramic honeycomb, products of NGK (Japan) having a diameter of86 mm, length of 25 mm and number of cells per unit area of 400, 600 and900 cell/in² were used. The ceramic honeycomb was washed with dilutedwater for several times using an ultrasonic cleaner before Wash-coatingto remove impurities remaining in the support. Then, it was dried in aconstant temperature/humidity chamber of 80° C. for 48 hr. γ-Aluminahaving an average particle size of about 1.487 μm was used as a support.γ-Alumina was mixed with diluted water (30 to 45 wt %). A bindercomprising 5 wt % of polyvinyl alcohol (PVA), 5 wt % of methyl celluloseand 2 wt % of phosphoric acid (H₃PO₄) was added to improve adhesivity.Then, hydrochloric acid was loaded to stabilize the mixture. The mixturewas strongly stirred for 2 hr. Zirconia balls having a diameter of 1.00mm, 3.00 mm and 5.00 mm were loaded to an attrition mill to 50 to 80% ofcapacity. The impeller rotating speed was 200 rpm, 400 rpm and 650 rpm.The alumina milling time was 10 hr.

Wash-coating was performed using the dip coater shown in FIG. 2. Theceramic honeycomb (400 cells/in², BET surface area=2.4 m²/g) was put inthe wash-coating reactor 1 and the wash-coating slurry prepared abovewas put in the storage tank 2. Dip coating was performed for 10 minuteswhile circulating the wash-coating slurry using the liquid pump 3.Excess slurry was removed with the air blower 4, and the ceramichoneycomb was dried in a constant temperature/humidity chamber of 110°C. and 85% relative humidity for 2 hr and then calcined at 600° C. for 4hr. The wash-coating slurry was wash-coated on the ceramic honeycomb bysingle, double and triple coatings. The γ-alumina coating amount wasabout 10 to 56% of the honeycomb support weight. The BET surface areaincreased from 2.4 m²/g up to 20 to 60 m²/g. The following Table 1 showsalumina coating amount and BET surface area for a variety of reactionconditions. TABLE 1 Slurry BET Ball-milling condition* particle Numberof Alumina surface Slurry Ball size size γ-alumina coating areaconcentration (mm) (μm) coatings amount (%) (m²/g) γ-Alumina 1 0.21 2 1523.6 (30 wt %) 3 30 31.5 3 0.35 3 36 21.5 γ-Alumina 1 0.42 1 12 29.6 (35wt %) 2 18 40.2 3 34 45.6 3 0.54 1 18 22.6 2 26 28.3 3 41 35.2 5 1.16 233 21.8 3 48 29.5 γ-Alumina 1 0.50 1 17 32.1 (40 wt %) 2 23 38.4 3 3845.2 3 0.74 1 21 28.3 2 35 33.2 3 43 38.4 5 1.23 1 25 26.1 2 38 30.8 349 36.8 γ-Alumina 1 0.72 1 29 31.0 (45 wt %) 2 42 33.4 3 56 29.5 3 1.161 32 26.3 2 47 33.1 5 1.35 1 30 24.2 2 50 23.4*Attrition mill operating condition: Impeller rotating speed = 650 rpm.Ceramic honeycomb support: NGK Co., Japan, cell density = 400 cells/in².

Example 1-B Honeycomb Support Wash-Coated with Boehmite Alumina

A wash-coated honeycomb support was prepared as in Example 1-A usingboehmite alumina instead of γ-alumina. The boehmite alumina coatingamount was up to 10 to 53% of the honeycomb support weight. The BETsurface area increased from 2.4 m²/g up to 30 to 60 m²/g. The followingTable 2 shows alumina coating amount and BET surface area for a varietyof reaction conditions. TABLE 2 Slurry BET Ball-milling condition*particle Number of Alumina surface Slurry Ball size size boehmitecoating area concentration (mm) (μm) coatings amount (%) (m²/g) Boehmite1 0.18 1 9 31.2 (30 wt %) 2 13 35.6 3 26 40.4 3 0.30 1 12 28.6 2 18 33.43 35 38.5 5 0.95 1 14 22.6 2 20 26.3 3 36 29.4 Boehmite 1 0.36 1 12 35.7(35 wt %) 2 19 43.8 3 30 51.6 3 0.49 1 17 32.1 2 26 40.3 3 38 43.5 51.05 1 20 28.6 2 31 35.1 3 45 40.2 Boehmite 1 0.46 1 15 42.6 (40 wt %) 220 51.2 3 35 60.0 3 0.69 1 21 34.8 2 35 43.8 3 40 50.2 5 1.12 1 24 30.42 36 38.5 3 45 45.0 Boehmite 1 0.65 1 25 33.1 (45 wt %) 2 38 40.5 3 5338.6 3 1.01 1 30 30.5 2 44 33.1 5 1.25 1 30 29.4 2 50 30.1*Attrition mill operating condition: Impeller rotating speed = 650 rpm.Ceramic honeycomb support: NGK Co., Japan, cell density = 400 cells/in².

As seen in Table 1 and Table 2, when the honeycomb supports were coatedat a slurry concentration ranging from 35 to 45 wt %, the coating amountof alumina and the resultant BET surface area were increased. And,boehmite alumina showed higher coating amount and BET surface area thanγ-alumina.

Example 2 Preparation of Structured Catalyst

Gasoline reforming transition metal catalyst powder was supported on thehoneycomb support of high surface area wash-coated with γ-alumina orboehmite to prepare a structured catalyst.

Example 2A Structured ICI Catalyst

A pellet type ICI catalyst (Imperial Chemical Industrial, England) wasmixed with diluted water to prepare a 20 wt % solution to obtain uniformcatalyst particle distribution for wash-coating. The mixture wasstabilized (pH 3) with hydrochloric acid and strongly stirred for 2 hr.Zirconia balls having a diameter of 1.00 mm, 3.00 mm and 5.00 mm wereloaded to an attrition mill to 70 to 80% of capacity. The impellerrotating speed was 200 rpm, 400 rpm and 650 rpm. The ICI catalystmilling time was 10 hr. The resultant wash-coated slurry was coated on aceramic honeycomb, a catalyst support.

The catalyst slurry was a supported on the alumina wash-coated ceramichoneycomb using the dip coater shown in FIG. 2. Excess slurry wasremoved with the air blower, and the ceramic honeycomb was dried in aconstant temperature/humidity chamber of 110° C. and 85% relativehumidity for 2 hr and then calcined at 600° C. for 4 hr. Thewash-coating slurry was wash-coated on the ceramic honeycomb by single,double and triple coatings. ICI catalyst was coated directly withoutalumina coating (Comparative Example 1). The following Table 3 shows ICIcatalyst supporting amount and BET surface area for a variety ofreaction conditions. TABLE 3 Number Catalyst BET Honeycomb support ofICI supporting surface Structured Slurry Number of catalyst amount areaICI catalyst concentration coatings coatings (%) (m²/g) A35ICI 2-1γ-Alumina 2 1 23 27.3 A35ICI 2-2 (35 wt %) 2 2 30 24.5 A35ICI 3-1 3 1 3732.1 A35ICI 3-2 3 2 44 26.4 A35ICI 3-3 3 3 53 23.7 Comparative 0 3 227.8 Example 1* A40ICI 3-1 γ-Alumina 3 1 43 30.1 A40ICI 3-2 (40 wt %) 3 251 26.3 A40ICI 3-3 3 3 60 22.5 B35ICI 1-1 Boehmite 1 1 15 21.7 B35ICI2-1 (35 wt %) 2 1 21 29.3 B35ICI 2-2 2 2 34 24.9 B35ICI 2-3 2 3 45 20.4B35ICI 3-1 3 1 34 38.2 B35ICI 3-2 3 2 41 34.6 B35ICI 3-3 3 3 51 29.3B40ICI 1-1 Boehmite 1 1 21 28.4 B40ICI 1-2 (40 wt %) 1 2 26 25.3 B40ICI1-3 1 3 39 20.6 B40ICI 2-1 2 1 26 37.4 B40ICI 2-2 2 2 36 34.3 B40ICI 2-32 3 47 30.8 B40ICI 3-1 3 1 41 46.3 B40ICI 3-2 3 2 49 42.9 B40ICI 3-3 3 358 34.3Attrition mill operating condition: Impeller rotating speed = 650 rpm;ball size = 1 mm.Ceramic honeycomb support: NGK Co., Japan, cell density = 400 cells/in².Comparative Example 1*: Directly coating ICI catalyst on honeycomb.

Example 2B Structured KIST Catalyst

A structured KIST catalyst was prepared as in Example 2A using gasolinereforming transition metal catalyst comprising 11.76% of Ni, 2.94% ofFe, 11.5% of Mg, 31.5% of Al and less than 0.005% of Ti and Zr asdisclosed in Example 3 of Korean Pat. Application No. 2002-21236. KISTcatalyst was coated directly without alumina coating (ComparativeExample 2). The following Table 4 shows KIST catalyst supporting amountand BET surface area for a variety of reaction conditions. TABLE 4Honeycomb support Number Catalyst BET Number of ICI supporting surfaceStructured Slurry of catalyst amount area ICI catalyst concentrationcoatings coatings (%) (m²/g) A35KIST 2-1 γ-Alumina 2 1 25 26.5 A35KIST2-2 (35 wt %) 2 2 32 25.5 A35KIST 3-1 3 1 39 33.4 A35KIST 3-2 3 2 4528.4 A35KIST 3-3 3 3 55 23.9 Comparative 0 3 25 8.1 Example 2* A40KIST2-1 γ-Alumina 2 1 28 23.8 A40KIST 3-1 (40 wt %) 3 1 44 31.4 A40KIST 3-23 2 54 23.2 A40KIST 3-3 3 3 62 23.5 B35KIST 1-1 Boehmite 1 1 17 22.1B35KIST 2-1 (35 wt %) 2 1 24 29.4 B35KIST 2-2 2 2 36 23.8 B35KIST 2-3 23 47 20.7 B35KIST 3-1 3 1 36 37.2 B35KIST 3-2 3 2 44 35.1 B35KIST 3-3 33 53 28.9 B40KIST 1-1 Boehmite 1 1 23 27.5 B40KIST 1-2 (40 wt %) 1 2 2925.8 B40KIST 1-3 1 3 41 21.4 B40KIST 2-1 2 1 27 38.1 B40KIST 2-2 2 2 4034.5 B40KIST 2-3 2 3 50 31.3 B40KIST 3-1 3 1 43 44.7 B40KIST 3-2 3 2 5142.4 B40KIST 3-3 3 3 63 37.3Attrition mill operating condition: Impeller rotating speed = 650 rpm;ball size = 1 mm.Ceramic honeycomb support: NGK Co., Japan, cell density = 400 cells/in².Comparative Example 2*: Directly coating KIST catalyst on honeycomb.

As seen in Table 3 and Table 4, when KIST catalyst (or ICI catalyst) wasdirectly coated without sub-micron sized alumina coating (ComparativeExamples 1 and 2), the resulting surface area was relatively small.Therefore, such catalysts are expected to have much lower catalyticactivity than the catalyst of the present invention.

TEST EXAMPLES

ATR reaction was performed as follows to test gasoline reforming.

The optimum reaction condition to test catalyst characteristics reportedby Moon, et al., the present inventors, was used [D. J. Moon, K.Sreekumar, S. D. Lee, B. J. Lee, H. S. Kim, Appl. Catal. A: General, 215(2001) 1].

Particularly, iso-octane, the representative material of gasoline, wasused as fuel of the gasoline reforming reaction.

The ATR reaction was performed with the conventional fixed bed reactorcomprising a reactant feeder, evaporator, POX reformer, water trap andon-line gas chromatograph (GC). Gaseous reactants such as hydrogen,nitrogen and air were pretreated and then fed to the reactor using amass flow controller. Liquid reactants such as iso-octane and water weresupplied to the evaporator at 0.003 to 0.3 ml/min and 0.007 to 0.6ml/min respectively using a liquid delivery pump (model M930, Young LinCo., Korea) after preheating to 350° C. The evaporator and POX reformerwere made by Inconel-600 tubes (outer diameter=1.25×10⁻² m, innerdiameter=9.5×10⁻³ m, and length=2×10⁻¹ m). Reaction temperature wasmeasured by mounting a chromel-alumel thermocouple at the inlet andoutlet of the catalyst bed. A PID temperature controller was used tocontrol the temperature change during reaction within +1° C. All lineswere heated to over 150° C., so that moisture contained in reactionproducts does not condensate. Temperature of each line was measured by athermocouple and recorded.

Test Example 1 POX Reforming Activity of KIST Catalyst

Iso-octane POX reforming reaction was performed using the structuredKIST catalyst prepared in Example 2. The structured catalyst was loadedin a kW-level gasoline reformer. Iso-octane POX reforming was performedin the presence of the structured catalyst under the condition of:temperature=500 to 800° C., space velocity=1,000 hr⁻¹ and molar ratiosof reactants: H₂O/C=3 and O/C=1. The gaseous reaction product wasanalyzed by an on-line gas chromatograph (TCD, HP 6890) after removingmoisture at the water trap. A carbosphere column (10″×1/8″ SS, 80/100meshes) was used for analysis. Constituents of the reaction product wereidentified by GC mass spectroscopy (HP 5890 GC, 5971A MSD).

The iso-octane POX reforming reaction result is shown in the followingTable 5. TABLE 5 POX reforming Product distribution (mol %) catalyst H₂CO CO₂ CH₄ B40KIST 1-1 48.07 35.96 10.73 5.24 B40KIST 1-2 49.04 34.2311.32 5.41 B40KIST 1-3 52.22 30.60 12.05 5.13 B40KIST 2-1 54.78 27.7511.24 6.23 B40KIST 2-2 57.03 24.14 12.44 6.39 B40KIST 2-3 56.07 25.9212.28 5.73 B40KIST 3-1 55.20 26.82 12.44 5.54 B40KIST 3-2 59.64 21.8411.91 6.61 B40KIST 3-3 57.77 23.75 10.76 7.72 A40KIST 3-1 50.32 32.1511.28 6.25 A40KIST 3-2 53.57 29.36 11.06 6.01 A40KIST 3-3 52.62 30.1411.02 6.22 Comparative 45.05 35.82 10.71 8.42 Example 3*Comparative Example 3*: KIST catalyst (Korean Pat. Application No.2002-21236) directly coated on honeycomb.Iso-octane POX reforming condition: Reaction temperature = 750° C.;space velocity = 1,000 hr⁻¹; molar ratios: H₂O/C = 3 and O/C = 1; celldensity = 400 cells/in².

The structured catalyst of the present invention which was prepared bysupporting catalyst powder on the honeycomb support wash-coatedsub-micron sized alumina showed significantly improved POX reformingcharacteristics compared with the KIST catalyst directly coated withoutalumina coating (Comparative Example 3), as seen in Table 5.

Test Example 2 Activity of Structured ICI Catalyst in POX ReformingReaction

Iso-octane POX reforming reaction was performed as in Test Example 1using the structured ICI catalyst prepared in Example 2.

The result is shown in the following Table 6. TABLE 6 POX reformingProduct distribution (mol %) catalyst H₂ CO CO₂ CH₄ B40ICI 1-1 47.0235.82 10.25 6.91 B40ICI 1-2 48.00 34.21 10.21 7.58 B40ICI 1-3 51.4431.45 10.62 6.49 B40ICI 2-1 53.45 28.59 10.53 7.43 B40ICI 2-2 57.2124.14 11.11 7.54 B40ICI 2-3 55.06 26.62 11.03 7.29 B40ICI 3-1 54.3528.21 10.46 6.98 B40ICI 3-2 57.65 23.21 11.12 8.02 B40ICI 3-3 56.0025.89 9.85 8.26 A40ICI 3-1 49.15 33.42 11.09 6.44 A40ICI 3-2 52.68 30.4211.25 5.65 A40ICI 3-3 51.34 31.23 10.40 7.03 Comparative 46.10 34.9210.23 8.75 Example 4*Comparative Example 4*: ICI catalyst (Imperial Chemical Industrial,England) directly coated on honeycomb.Iso-octane POX reforming condition: Reaction temperature = 750° C.;space velocity = 1,000 hr⁻¹; molar ratios: H₂O/C = 3 and O/C = 1; celldensity = 400 cells/in².

The structured catalyst of the present invention which was prepared bysupporting catalyst powder on the honeycomb support wash-coatedsub-micron sized alumina showed significantly improved POX reformingcharacteristics compared with the ICI catalyst directly coated withoutalumina coating (Comparative Example 4), as seen in Table 6.

As described above, the structured catalyst of the present invention,which is prepared by supporting catalyst powder having gasoline POXreforming activity on the ceramic honeycomb support wash-coated withsub-micron sized alumina, shows significantly improved catalystcharacteristics than the KIST catalyst and ICI catalyst prepared bydirect coating without coating sub-micron sized alumina catalyst(Comparative Example 3 and Comparative Example 4).

Accordingly, the structured catalyst of the present invention is veryuseful as a gasoline reforming catalyst for fuel-cell powered vehicles.

Also, the structured catalyst of the present invention can be applied togas stations for manufacturing high-purity hydrogens or petrochemicalprocesses for manufacturing synthetic gases.

And, the hydrogen reformed by the ATR reaction may be passed through aseries of high temperature water gas shift (HTS) reactor, lowtemperature water gas shift (LTS) reactor and/or preferential partialoxidation (PROX) reactor to reduce the CO concentration, and thenprovided to a polymer electrolyte membrane (PEM) fuel cell for afuel-cell powered vehicle.

While the present invention has been described in detail with referenceto the preferred embodiments, those skilled in the art will appreciatethat various modifications and substitutions can be made thereto withoutdeparting from the spirit and scope of the present invention as setforth in the appended claims.

1. A structured catalyst for reforming of gasoline comprising a gasolinereforming transition metal catalyst supported on the ceramic honeycombsupport having a BET surface area ranging from 20 to 60 m²/g wash-coatedwith sub-micron sized alumina and its precursor.
 2. The gasolinereforming structured catalyst of claim 1, wherein said transition metalcatalyst is an ICI catalyst.
 3. The gasoline reforming structuredcatalyst of claim 1, wherein said transition metal catalyst comprises 5to 15 wt % of Mg, as a metal preventing carbon deposition, withreference to the amount of the total catalyst and at least twotransition metals, as promoters, selected from the group consisting ofNi, Co, Fe, Mo, Cr, Ti and Zr supported on a porous support such asγ-alumina and silica-alumina.
 4. The gasoline reforming structuredcatalyst of claim 3, wherein said promoters respectively comprise 0.1 to15 wt % of Ni or Co, 2 to 15 wt % of Fe or Mo, 0.1 to 1.0 wt % of Cr or0 to 0.005 wt % of Ti or Zr with reference to the amount of the totalcatalyst.
 5. A method of preparing a structured catalyst for reformingof gasoline for fuel-cell powered vehicles comprising the steps of: 1)preparing an aqueous alumina solution with a pH 2 to 5; 2) adding 2 to 7wt % of polyvinyl alcohol, 3 to 7 wt % of methyl cellulose and 1 to 5 wt% of phosphoric acid based on 100 wt % of the solid content of theaqueous alumina solution, stirring and ball-milling the same to preparean alumina slurry; 3) coating the alumina slurry on a ceramic honeycombsupport; 4) ball-milling of gasoline reforming transition metal catalystpowder to prepare a catalyst slurry; and 5) wash-coating the catalystslurry to prepare a structured catalyst.
 6. The method of preparing astructured catalyst for reforming of gasoline for fuel-cell poweredvehicles of claim 5, wherein said support wash-coated with alumina havea BET surface area ranging from 20 to 60 m²/g.
 7. The method ofpreparing a structured catalyst for reforming of gasoline for fuel-cellpowered vehicles of claim 5, wherein said alumina slurry forwash-coating the support have a concentration ranging from 30 to 45 wt%.
 8. The method of preparing a structured catalyst for reforming ofgasoline for fuel-cell powered vehicles of claim 5, wherein 0 to 7 wt %of polyvinyl alcohol, 0 to 7 wt % of methyl cellulose and 0 to 5 wt % ofphosphoric acid are added as binder during the preparation of thecatalyst slurry with reference to 100 wt % of the transition metalcatalyst powder.
 9. The method of preparing a structured catalyst forreforming of gasoline for fuel-cell powered vehicles of claim 5, whereinsaid support wash-coated with alumina and said structured catalyst aredried in a constant temperature/humidity chamber of 60 to 110° C. and 60to 90% relative humidity, and then calcined at 500 to 700° C. in air.10. A method of preparing a synthetic gas containing hydrogen and carbonmonoxide by autothermal reforming reaction of gasoline, wherein saidreforming reaction is performed in the presence of the structuredcatalyst selected from claims 1 to 4 under the condition: reactiontemperature=600 to 1000° C.; space velocity=1,000 to 50,000 hr⁻¹; andmolar ratios: H₂O/C=0.1 to 5 and O/C=0.1 to 3.